Whenis awh-word. We usewhento ask questions, as a conjunction and to introduce relative clauses.
Whenas a question word
We can usewhento ask for information about what time something happens:
Whendid you leave?
Whenare you going on holiday?
Whenwill you know the result of the exam?
We can usewhenin indirect questions:
She asked mewhenI would be ready to start the job.
I wonderwhenthe new computers will arrive.
See also:
Questions
Questions:wh-questions
Future
Whenas a conjunction
We usewhenas a conjunction meaning ‘at the time that’. The clause withwhenis a subordinate clause (sc) and needs a main clause (mc)to complete its meaning. If thewhen-clause comes before the main clause, we use a comma.
Talking about the past
[SC]WhenI was young,[MC]there were no houses here.
[MC]Nobody spoke[SC]whenshe came into the room.
Talking about the present
Whenyou start the engine, there’s a strange noise.
Talking about the future
In references to the future withwhen, we use the present simple or the present perfect in thewhen-clause, not the future withshallandwill:
Whenthe new parkopens, I’ll go there every day.
Not:When the new park will open, I’ll go there every day.
WhenI’vefinishedmy homework, I’m going to phone Marita.
Not:When I’ll finish my homework, I’m going to phone Marita.
We can usewhenas a conjunction to mean ‘considering that’:
What’s the point in going outwhenwe have to be home by eleven o’clock?
See also:
Conjunctions
Punctuation
As
Whenas a relative pronoun
We can usewhenas a relative pronoun in relative clauses:
That was the weekwhenwe booked our holiday.
The parcel arrived in the post at 11 am,whenI was still at work.
See also:
Relative clauses
Since when?
We can usesince whento ask at what time something began. We often use it as a response when we are surprised that something has begun:
A:Hilary’s working at the Art Museum now.
B:Really?Since when?
A:Oh, she’s been there about three months.
UsingSince whenat the start of a question can express anger or sarcasm:
[talking about children watching television]
A:Maybe you should try not to let them watch so much television.
B:Since whenare you an expert on childcare?(This is very direct.)
Whenorif?
Weusewhento refer to a future situation or condition that we are certain of, whereas we useifto introduce a possible or unreal situation.
| I will definitely see Gary. |
| I may see Gary but I am not certain. |
See also:
Iforwhen?
Whenorsince?
We usewhento mean ‘(at) the time that’. We usesinceto refer to a particular time in the past until another time or until now:
I had a great timewhenI went to the coast.
I have been having a boring timesinceI came back home.
Not:I have been having a boring time when I came back home.
See also:
Since
When: typical errors
Be careful not to usewheninstead ofif:
Ifyou arrive too late, you are not allowed to take the examination because they don’t accept late enrolment.
Not:When you arrive too late, …
Be careful not to usewheninstead ofsince:
I was very surprised to see him because it’s been a long timesinceI last saw him.
Not: …it’s been a long time when I last saw him.
We don’t usewillafterwhento mean ‘at that time’:
WhenIstartcollege, I’ll miss my old school friends.
Not:When I’ll start college, I’ll miss my old school friends.